Medical Definition of antagonist
: an agent that acts in physiological opposition <contact between a tooth and its antagonist in the opposing jaw>: asa: a muscle that contracts with and limits the action of an agonist with which it is paired—called also ; compare agonist 1, synergist 2b: a chemical that acts within the body to reduce the physiological activity of another chemical substance (as an opiate); especially : one that opposes the action on the nervous system of a drug or a substance occurring naturally in the body by combining with and blocking its nervous receptor—compare agonist 2
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Dictionary: Definition of "antagonist" Thesaurus: All synonyms and antonyms for "antagonist" Spanish Central: Translation of "antagonist" Nglish: Translation of "antagonist" for Spanish speakers Britannica English: Translation of "antagonist" for Arabic speakers Britannica.com: Encyclopedia article about "antagonist"
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